Knee prosthesis systems and methods

ABSTRACT

A knee prosthesis system constructed in accordance to one example of the present disclosure can include a femoral component, a tibial component, a first femoral component insert, a second femoral component insert, a first tibial bearing, and a second tibial bearing. The knee prosthesis system may be configured in one of a non-hinged configuration and a second hinged configuration. In the first non-hinged configuration, the first femoral component insert is positioned relative to the femoral component and the first tibial bearing is positioned onto the tibial component. In the second hinged configuration, the second femoral component insert is positioned relative to the femoral component and the second tibial bearing is positioned onto the tibial component.

FIELD

The present disclosure relates generally to knee joint prostheses andmore particularly, to a knee prosthesis system having a femoralcomponent, a bearing component, a tibial component, and a collection ofinserts that may be selectively and alternatively used to convert thefemoral component and tibial component for use in at least one of eithera non-hinged configuration and a hinged configuration.

BACKGROUND

This section provides background information related to the presentdisclosure which is not necessarily prior art.

A knee joint prosthesis typically comprises a femoral component, abearing component, and a tibial component. The femoral component andtibial component are designed to be surgically attached to the distalend of the femur and the proximal end of the tibia, respectively. Thefemoral component is further designed to cooperate with the bearing inconjuction with the tibial component in simulating the articulatingmotion of an anatomical knee joint. Such knee joint prostheses aregenerally referred to as primary knee prostheses.

Knee joint prostheses, in combination with ligaments and muscles,attempt to duplicate natural knee motion as well as absorb and controlforces generated during the range of flexion. In some instances however,it may be necessary to replace an existing prosthesis. Such replacementprostheses are generally referred to as revision knee prostheses.Depending on the degree of damage or deterioration of the primary kneeprosthesis, knee tendons and ligaments, however, it may be necessary fora revision knee joint prosthesis to eliminate one or more of thesemotions in order to provide adequate stability. In this way, it may bedesirable to provide a fully constrained revision knee, a posteriorstabilized (PS) revision knee, or a hinged revision knee for example.

SUMMARY

This section provides a general summary of the disclosure, and is not acomprehensive disclosure of its full scope or all of its features.

A knee prosthesis system constructed in accordance to one example of thepresent disclosure can include a femoral component, a tibial component,a first femoral component insert, a second femoral component insert, afirst tibial bearing, and a second tibial bearing. The knee prosthesissystem may be configured in one of a first non-hinged configuration anda second hinged configuration. In the first non-hinged configuration,the first femoral component insert is positioned relative to the femoralcomponent and the first tibial bearing is positioned onto the tibialcomponent. In the second hinged configuration, the second femoralcomponent insert is positioned relative to the femoral component and thesecond tibial bearing is positioned onto the tibial component.

The femoral component can include a medial and lateral condyle portionconnected by a patellar track portion and a femoral box. The femoral boxcan define a first pair of passages therethrough. The tibial componentcan have a platform portion and an inferiorly extending stem. The firstfemoral component insert can have a first pair of closed walls. Thefirst femoral component insert can be sized to selectively locate at thefemoral box. The second femoral component insert can have a second pairof walls that define a second pair of passages therethrough. The secondfemoral component insert can be sized to selectively locate at thefemoral box wherein the first and second pair of passages cooperativelyalign for receipt of an axle. The first tibial bearing can have firstbearing surfaces that are configured to engage the medial and lateralcondyle portions. The second tibial bearing can have second bearingsurfaces that are configured to engage the medial and lateral condyleportions. The second tibial bearing can further comprise a superiorlyextending portion defining an axle passage.

According to additional features, the tibial component can furthercomprise a first interlocking detail configured thereon. The kneeprosthesis system can further comprise a first tibial tray insert havinga first bearing opposing structure and a second interlocking detailconfigured thereon. A second tibial tray insert can have a secondbearing opposing structure and a third interlocking detail thereon. Thefirst and second tibial tray inserts can be selectively andalternatively coupled to the tibial component. The first bearingengaging structure can be configured to cooperate with the first tibialbearing in a fixed relationship. The second bearing engaging structurecan be configured to cooperate with the second tibial bearing in arotating relationship.

According to still other features, the first interlocking detail cancomprise one of a male and female dovetail. The second and thirdinterlocking detail may comprise the other of the male and femaledovetail. A fastener can be selectively and alternatively coupled to thefirst and second femoral component inserts to the femoral component. Alocking bar can be configured to selectively couple the first tibialbearing to the first tibial tray insert.

According to other features, the first bearing opposing structure of thefirst tibial tray insert can comprise a pair of posts that areintegrally formed on a superior surface at an anterior edge thereof. Aretaining rail can extend from a posterior edge thereof. The locking barcan be configured to selectively engage the pair of posts and the firsttibial bearing in the first non-hinged configuration. The second tibialtray insert can include a superiorly extending post configured to bereceived at the superiorly extending portion of the second tibialbearing in the second hinged configuration.

According to still other features, the knee prosthesis system canfurther comprise a third tibial tray insert having a fourth interlockingdetail configured to selectively mate with the first interlocking detailof the tibial component. The third tibial tray insert can have a bodyportion sized to oppose substantially all of the platform portion of thetibial component.

A method for implanting a knee prosthesis according to the presentdisclosure can include providing a knee prosthesis system including afemoral component having a femoral box defining a first pair ofpassages, a tibial component having a platform, a first femoralcomponent insert having a first pair of closed walls, and a secondfemoral component insert having a second pair of walls that define asecond pair of passages therethrough. One of the first and secondfemoral component inserts may be intraoperatively removed from thefemoral box. The other of the first and second femoral component insertsmay be positioned adjacent the femoral box. Removing and positioning thefirst and second femoral component inserts can convert the kneeprosthesis system between a non-hinged configuration and a hingedconfiguration.

Further areas of applicability will become apparent from the descriptionprovided herein. The description and specific examples in this summaryare intended for purposes of illustration only and are not intended tolimit the scope of the present disclosure.

DRAWINGS

The drawings described herein are for illustrative purposes only ofselected embodiments and not all possible implementations, and are notintended to limit the scope of the present disclosure.

FIG. 1 is a front perspective view of a knee prosthesis systemconstructed in accordance to one example of the present disclosure;

FIG. 2 is an exploded view of various components of the knee prosthesissystem of FIG. 1 configured for use in a first non-hinged configuration;

FIG. 3 is a partial exploded view of the components shown in FIG. 2 andillustrating a first femoral component insert coupled to the femoralcomponent according to one configuration;

FIG. 4 is a front perspective view of the components shown in FIG. 2 inan assembled, non-hinged configuration;

FIG. 5 is an exploded perspective view of various components of the kneeprosthesis system of FIG. 1 configured for use in a first hingedconfiguration;

FIG. 6 is a partial exploded view of the components of FIG. 5 and shownwith a second femoral component insert coupled to the femoral componentaccording to one example; and

FIG. 7 is a front perspective view of the knee prosthesis componentsshown in FIG. 5 in an assembled, hinged configuration.

Corresponding reference numerals indicate corresponding parts throughoutthe several views of the drawings.

DETAILED DESCRIPTION

Example embodiments will now be described more fully with reference tothe accompanying drawings.

At the outset, the instant disclosure provides a knee prosthesis systemhaving various knee prostheses that may be adapted for use in a revisionknee procedure. Various components are described that may be used aloneor as part of a posterior stabilized (PS) knee revision, fullyconstrained knee revision, and hinged knee revision. As will become moreappreciated from the following discussion, the instant disclosurefurther provides various adapters that may be used in any combinationwith a tibial and femoral component disclosed herein. Moreover,selection of any of the described components from the knee prosthesissystem may be selected intraoperatively by the surgeon performing theprocedure.

With initial reference to FIG. 1, a knee prosthesis system constructedin accordance to one example of the present disclosure is shown andgenerally identified as reference numeral 10. As will becomeappreciated, the knee prosthesis system 10 can provide variouscomponents and adapters that may be intraoperatively exchanged toconvert a single femoral component and a single tibial component for usein either a first non-hinged configuration (FIG. 4) or a second hingedconfiguration (FIG. 6).

The knee prosthesis system 10 can generally include a femoral component12, a tibial component 14, a first femoral component insert 16, a secondfemoral component insert 18, a first tibial bearing 20, a second tibialbearing 22, a first tibial tray insert 24, a second tibial tray insert26, and a third tibial tray insert 28. The knee prosthesis system canfurther comprise an axle 30, a locking bar 32, and a fastener 34. Aswill become appreciated herein, the knee prosthesis system 10 allows asurgeon to use a common femoral component 12 and tibial component 14 forapplications that require both a non-hinged configuration and a hingedconfiguration. For example, in a first non-hinged configuration, and asfurther shown in FIGS. 2-4, a surgeon may use the femoral component 12,the first femoral component insert 16, the fastener 34, the first tibialbearing 20, the tibial component 14, the first tibial tray insert 24,and the locking bar 32. Alternatively, a surgeon may determine that aparticular patient will require a more constrained configuration. When amore constrained configuration may be desirable, a surgeon may use theknee prosthesis system 10 to create a hinged configuration.

In a hinged configuration, and as further shown in FIGS. 5-7, a surgeonmay use the femoral component 12, the second femoral component insert18, the axle 30, the fastener 34, the second tibial bearing 22, thetibial component 14, and the second tibial tray insert 26. In oneadvantage of the knee prosthesis system 10 according to the presentdisclosure, a surgeon may intraoperatively exchange components toconvert the prosthesis between a hinged and a non-hinged configurationwithout disturbing the femoral component 12 and the tibial component 14.In this way, it is contemplated that in one example, a surgeon may haveimplanted the knee prosthesis system 10 in a non-hinged configurationand, over time, the knee joint of the patient may deteriorate. In suchan example, a surgeon may surgically access the implanted non-hingedknee prosthesis and exchange the first femoral component insert 16 for asecond femoral component insert 18, the first tibial bearing 20 for thesecond tibial bearing 22, and the first tibial tray insert 24 with thesecond tibial tray insert 26. The axle 30 may be used to hingedly couplethe femoral component 12 to the second tibial bearing 22. As describedherein, the first tibial bearing 20 is a fixed bearing whereas thesecond tibial bearing 22 is a rotating bearing.

Returning now to FIG. 1, the femoral component 12 will be described ingreater detail. The femoral component 12 can generally comprise a medialcondyle portion 40 and a lateral condyle portion 42. The condyleportions 40 and 42 can replace the medial and lateral condyles of adistal femur. The medial and lateral condyle portions 40 and 42 caninterconnect through a femoral box 44 and a patellar track portion 46.The femoral box 44 can generally comprise a pair of generally parallelwalls 50 that connect through a connecting wall 52. The walls 50 definea first pair of passages 56 therethrough. The connecting wall 52 candefine a bore 58. It will be appreciated that the femoral component 12may comprise other features and/or be configured differently withoutdeparting from the scope of the present disclosure.

The tibial component 14 can generally include a platform portion 60having an inferior bone engaging surface 62 and a superior bearingopposing surface 64. The platform portion 60 can further provide a firstinterlocking detail 66 on the superior bearing opposing surface 64. Inone example, the first interlocking detail 66 can provide a slot 68having a female dovetail 70. A tibial stem 72 can extend generallyinferiorly from the tibial component 14.

The first femoral component insert 16 can generally have a first pair ofclosed walls 76 that are connected by a transverse wall 78. A hole 80may be formed through the transverse wall 78. In general, the firstfemoral component insert 16 can be dimensioned so as to fit between thewalls 50 on the femoral box 44 of the femoral component 12 (see FIG. 4).The second femoral component insert 18 can generally comprise a pair oflateral walls 86 that define second passages 88 therethrough. Atransverse wall 90 generally connects the walls 86. A hole 92 may beformed through the transverse wall 90. As with the first femoralcomponent insert 16 described above, the second femoral component insert18 may be dimensioned so as to fit between the walls 50 of the femoralbox 44 on the femoral component 12 (see FIG. 6).

The first tibial bearing 20 can include first bearing surfaces 98configured to engage the medial and lateral condyle portions 40 and 42of the femoral component 12. The first tibial bearing 20 can furthercomprise engaging structure 100 formed on an inferior side 102 thereof.A superiorly extending portion 104 may be formed on the first tibialbearing 20. The first tibial bearing 20 can be formed of ultra-highmolecular weight polyethylene (UHMWPE).

The second tibial bearing 22 can generally include first bearingsurfaces 110 configured to engage the medial and lateral condyleportions 40 and 42 of the femoral component 12. The second tibialbearing 22 can further include a post bore 112 defined therein. Asuperiorly extending portion 114 can define an axle passage 116therethrough. The second tibial bearing 22 can additionally includestructure that interfaces with the inserts 26 and 28 and/or the tibialcomponent 14 to inhibit liftoff. The second tibial bearing 22 can beformed from a surgical grade, low-friction, and low-wearing plastic,such as UHMWPE or other suitable material. Other tibial bearingconfigurations may also be employed. For example, the bearings can belinked or non-linked. Additionally, fixed and rotating platform bearingsmay also be used. In still other examples, a one-piece tibial tray canincorporate various bearings to go between non-linked and linked. Suchexamples may be found in Applicants' co-pending owned U.S. patentapplication Ser. No. (Docket No. 5490-000637/US/CPI), filed ______,entitled KNEE JOINT PROSTHESIS SYSTEM AND METHOD FOR IMPLANTATION, whichis filed concurrently herewith and incorporated by reference in itsentirety.

The first tibial tray insert 24 can generally include a first bearingopposing structure 120 and a second interlocking detail 122. In theexample shown, the second interlocking detail 122 is in the form of amale dovetail 124. The first tibial tray insert 24 can further comprisea pair of posts 126 integrally formed on a superior surface at ananterior edge thereof. A retaining rail 130 may extend from a posterioredge thereof. As will be described herein, the posts 126 and retainingrail 130 may cooperate with the locking bar 32 to engage and couple withthe engaging structure 100 on the first tibial bearing 20. The retainingrail 130 can define a retaining slot 134. The second tibial tray insert26 can include a second interlocking detail 142 in the form of a maledovetail 144. The second tibial tray insert 26 can further comprise apost 146 extending superiorly therefrom. The third tibial tray insert 28may be formed similarly to the second tibial tray insert 26. However,the third tibial tray insert 28 may include a body portion 150 that cangenerally extend substantially across the profile of the platformportion 60 of the tibial component 14. The third tibial tray insert 28can include a third interlocking detail 152 in the form of a maledovetail 154. The third tibial tray insert 28 can further comprise apost 156 extending superiorly therefrom.

The locking bar 32 can generally include a body 160 having a finger 162extending therefrom. A catch 164 can be formed on a terminal end of thefinger 162. The body 160 can further include a leading end 166 and atrailing end 168. The locking bar 32 can be formed of biocompatiblemetallic material, such as titanium for example.

With particular reference now to FIGS. 2-4, a method for assembling theknee prosthesis system 10 in a first non-hinged configuration will bedescribed. The first femoral component insert 16 may be generallylocated between the walls 50 of the femoral box 44 on the femoralcomponent 12. In this regard, the closed walls 76 can act to close thefirst passages 56 on the femoral component 12. The fastener 34 may beadvanced through the hole 80 in the first femoral component insert 16and coupled to the connecting wall 52 such as at threads formed on thebore 58. In another example, the first femoral component insert 16 canbe optional.

The first tibial tray insert 24 can be slidably coupled to the tibialcomponent 14. In one example, the second interlocking detail 122 can beadvanced along the first interlocking detail 66 on the tibial component14. In this regard, the female dovetail 70 on the tibial component 14can lockingly couple with the corresponding male dovetail 124 on thefirst tibial tray insert 24. The first tibial bearing 20 can then belocated onto the first tibial tray insert 24 and tibial component 14.The engaging structure 100 of the first tibial bearing 20 cancooperatively align with the respective posts 126 and retaining rail130. The locking bar 32 can then be advanced between the engagingstructure 100 of the first tibial bearing 20 and the posts 126 on thefirst tibial tray insert 24. A more detailed discussion of how thelocking bar 32 cooperates with the posts 126 and corresponding bearingmay be found in commonly owned U.S. Pat. No. 5,330,534 entitled “KneeJoint Prosthesis With Interchangeable Components”, which is herebyincorporated by reference. In other examples, the tibial component 14and the first tibial bearing 20 can be integrally formed. An example ofhow the tibial component 14 and the first tibial bearing 20 can beformed can be found in the Vanguard® Mono-Lock™ Tibial System by Biomet.

Turning now to FIGS. 5-7, a method for assembling the knee prosthesissystem 10 in a second hinged configuration will be described in greaterdetail. It will be appreciated that in some examples, the correspondingcomponents required for the non-hinged configuration are first removedfrom cooperation with the femoral component 12 and the tibial component14. The second femoral component insert 18 can be located between thewalls 50 on the femoral component 12. The second femoral componentinsert 18 can be positioned such that the second passages 88 align withthe first passages 56 on the femoral box 44. The fastener 34 can also beadvanced through the hole 92 and the bore 58 to couple the secondfemoral component insert 18 to the femoral component 12. In anotherexample, the second femoral component insert 18 can be optional. In someexamples, the fastener 34 can act as a superiorly extending stem.Additionally or alternatively, a separate stem can be incorporated.While a fastener 34 is shown coupling the first and second femoralcomponent inserts 16 and 18, other attachment methods may be employed.In yet other examples, the femoral box 44 can be formed without thepassages 56. The axle 30 can be retained entirely within the secondfemoral component insert 18.

The second interlocking detail 142 of the second tibial tray insert 26can be slidably advanced into engagement with the first interlockingdetail 66 on the tibial component 14. Specifically, the female dovetail70 on the tibial component 14 can receive the male dovetail 144 on thesecond tibial tray insert 26. It will be appreciated that while thedovetails 70 and 144 (and others disclosed herein) are shown extendingalong an anterior/posterior direction, they may extend along otherdirections such as medial/lateral or superior/inferior. In otherexamples, the dovetails disclosed herein can be replaced with otherstructures including slots, various diameters, locking bars, etc. Thesecond tibial bearing 22 can then be located relative to the secondtibial tray insert 26. In one example, the post bore 112 can receive thepost 146. The axle 30 can then be advanced through all of the firstpassages 56 on the femoral box 44 of the femoral component 12, thesecond passages 88 on the second femoral component insert 18, and theaxle passage 116 of the second tibial bearing 22.

In other examples, it may be desirable to implant a femoral componenthaving a stem. For example, in instances where a posterior stabilizedimplant is implanted, an insert (such as the first femoral insert 16)can be removed to expose the femoral canal. The femur can be preparedfor receipt of a stem between the condyles. A stemmed femoral insert (orother structure) can then be installed on the femoral component andimplanted.

The foregoing description of the embodiments has been provided forpurposes of illustration and description. It is not intended to beexhaustive or to limit the disclosure. Individual elements or featuresof a particular embodiment are generally not limited to that particularembodiment, but, where applicable, are interchangeable and can be usedin a selected embodiment, even if not specifically shown or described.The same may also be varied in many ways. Such variations are not to beregarded as a departure from the disclosure, and all such modificationsare intended to be included within the scope of the disclosure.

Example embodiments are provided so that this disclosure will bethorough, and will fully convey the scope to those who are skilled inthe art. Numerous specific details are set forth such as examples ofspecific components, devices, and methods, to provide a thoroughunderstanding of embodiments of the present disclosure. It will beapparent to those skilled in the art that specific details need not beemployed, that example embodiments may be embodied in many differentforms and that neither should be construed to limit the scope of thedisclosure. In some example embodiments, well-known processes,well-known device structures, and well-known technologies are notdescribed in detail.

The terminology used herein is for the purpose of describing particularexample embodiments only and is not intended to be limiting. As usedherein, the singular forms “a,” “an,” and “the” may be intended toinclude the plural forms as well, unless the context clearly indicatesotherwise. The terms “comprises,” “comprising,” “including,” and“having,” are inclusive and therefore specify the presence of statedfeatures, integers, steps, operations, elements, and/or components, butdo not preclude the presence or addition of one or more other features,integers, steps, operations, elements, components, and/or groupsthereof. The method steps, processes, and operations described hereinare not to be construed as necessarily requiring their performance inthe particular order discussed or illustrated, unless specificallyidentified as an order of performance. It is also to be understood thatadditional or alternative steps may be employed.

When an element or layer is referred to as being “on,” “engaged to,”“connected to,” or “coupled to” another element or layer, it may bedirectly on, engaged, connected or coupled to the other element orlayer, or intervening elements or layers may be present. In contrast,when an element is referred to as being “directly on,” “directly engagedto,” “directly connected to,” or “directly coupled to” another elementor layer, there may be no intervening elements or layers present. Otherwords used to describe the relationship between elements should beinterpreted in a like fashion (e.g., “between” versus “directlybetween,” “adjacent” versus “directly adjacent,” etc.). As used herein,the term “and/or” includes any and all combinations of one or more ofthe associated listed items.

Although the terms first, second, third, etc. may be used herein todescribe various elements, components, regions, layers and/or sections,these elements, components, regions, layers and/or sections should notbe limited by these terms. These terms may be only used to distinguishone element, component, region, layer or section from another region,layer or section. Terms such as “first,” “second,” and other numericalterms when used herein do not imply a sequence or order unless clearlyindicated by the context. Thus, a first element, component, region,layer or section discussed below could be termed a second element,component, region, layer or section without departing from the teachingsof the example embodiments.

Spatially relative terms, such as “inner,” “outer,” “beneath,” “below,”“lower,” “above,” “upper,” and the like, may be used herein for ease ofdescription to describe one element or feature's relationship to anotherelement(s) or feature(s) as illustrated in the figures. Spatiallyrelative terms may be intended to encompass different orientations ofthe device in use or operation in addition to the orientation depictedin the figures. For example, if the device in the figures is turnedover, elements described as “below” or “beneath” other elements orfeatures would then be oriented “above” the other elements or features.Thus, the example term “below” can encompass both an orientation ofabove and below. The device may be otherwise oriented (rotated 90degrees or at other orientations) and the spatially relative descriptorsused herein interpreted accordingly.

1. A knee prosthesis system comprising: a femoral component havingmedial and lateral condyle portions connected by a patellar trackportion and a femoral box, the femoral box defining a first pair ofpassages therethrough; a tibial component having a platform portion andan inferiorly extending stem; a first femoral component insert having afirst pair of closed walls, the first femoral component insert sized toselectively locate at the femoral box; a second femoral component inserthaving a second pair of walls that define a second pair of passagestherethrough, the second femoral component insert sized to selectivelylocate at the femoral box wherein the first and second pairs of passagescooperatively align for receipt of an axle; a first tibial bearinghaving first bearing surfaces configured to engage the medial andlateral condyle portions; and a second tibial bearing having secondbearing surfaces configured to engage the medial and lateral condyleportions, the second tibial bearing further comprising a superiorlyextending portion defining an axle passage; wherein the knee prosthesissystem is configured in one of a first non-hinged configuration and asecond hinged configuration, wherein in the first non-hingedconfiguration the first femoral component insert is positioned at thefemoral box of the femoral component and the first tibial bearing ispositioned onto the tibial component, wherein in the second hingedconfiguration the second femoral component insert is positioned at thefemoral box and the axle is located through the first and secondpassages and the second tibial bearing is positioned onto the tibialcomponent.
 2. The knee prosthesis system of claim 1 wherein the tibialcomponent further comprises a first interlocking detail configuredthereon.
 3. The knee prosthesis system of claim 2 further comprising: afirst tibial tray insert having a first bearing engaging structure and asecond interlocking detail configured thereon; and a second tibial trayinsert having a second bearing engaging structure and a thirdinterlocking detail thereon; wherein the first and second tibial trayinserts are selectively and alternatively coupled to the tibialcomponent, the first bearing engaging structure configured to cooperatewith the first tibial bearing in a fixed relationship, the secondbearing engaging structure configured to cooperate with the secondtibial bearing in a rotating relationship.
 4. The knee prosthesis systemof claim 3 wherein the first interlocking detail comprises one of a maleand female dovetail and the second and third interlocking details bothcomprise the other of the male and female dovetail.
 5. The kneeprosthesis system of claim 1 further comprising a fastener thatselectively and alternatively couples the first and second femoralcomponent inserts to the femoral component.
 6. The knee prosthesissystem of claim 3 further comprising a locking bar configured toselectively couple the first tibial bearing to the first tibial trayinsert.
 7. The knee prosthesis system of claim 6 wherein the firstbearing engaging structure of the first tibial tray insert comprises apair of posts integrally formed on a superior surface at an anterioredge and a retaining rail extending from a posterior edge thereof,wherein the locking bar is configured to selectively engage the pair ofposts and the first tibial bearing in the first non-hingedconfiguration.
 8. The knee prosthesis system of claim 3 wherein thesecond tibial tray insert includes a superiorly extending postconfigured to be received at the superiorly extending portion of thesecond tibial bearing in the second hinged configuration.
 9. The kneeprosthesis system of claim 3 further comprising a third tibial trayinsert having a fourth interlocking detail configured to selectivelymate with the first interlocking detail of the tibial component, thethird tibial tray insert having a body portion sized to opposesubstantially all of the platform portion of the tibial component.10.-19. (canceled)
 20. A knee prosthesis system comprising: a femoralcomponent comprising: a medial condyle portion; a lateral condyleportion; a patellar track portion connecting the medial and lateralcondyle portions; medial and lateral walls located between the medialand lateral condyle portions posterior of the patellar track portion;and a pair of passages extending through the medial and lateral walls,respectively, to define a first axle passage; a femoral component inserthaving a first pair of walls, the femoral component insert sized toselectively locate between the medial and lateral walls; and a tibialcomponent comprising: a bearing portion having first bearing surfacesconfigured to engage the medial and lateral condyle portions; and atibial stem extending inferiorly relative to the bearing portion. 21.The knee prosthesis system of claim 20, wherein the first pair of wallscomprise closed walls.
 22. The knee prosthesis system of claim 20,wherein the first pair of walls include a first pair of bores that areconfigured to align with the pair of passages when the femoral componentinsert is positioned between the medial and lateral walls.
 23. The kneeprosthesis system of claim 20, wherein the tibial component furthercomprises: a platform comprising: a superior surface that is configuredto couple to the bearing portion; and an inferior surface from which thetibial stem extends; and a superiorly extending portion extending fromthe tibial bearing, the superiorly extending portion configured to bepositioned between the first pair of walls.
 24. The knee prosthesissystem of claim 23, wherein the first pair of walls form a socketdefining a femoral box.
 25. The knee prosthesis system of claim 24,wherein: the femoral component insert further comprises a transversewall connecting the first pair of walls; and the femoral componentfurther comprises a connecting wall spanning a gap between the medialand lateral walls.
 26. The knee prosthesis system of claim 25, wherein:the transverse wall is configured to contact the connecting wall whenthe femoral component insert is positioned between the medial andlateral walls; and the first pair of walls is configured to contact thesuperiorly extending portion when the superiorly extending portion isinserted between the first pair of walls.
 27. The knee prosthesis systemof claim 25, wherein: the transverse wall includes a first hole; and theconnecting wall includes a second hole configured to align with thefirst hole when the femoral component insert is positioned between themedial and lateral walls.
 28. The knee prosthesis system of claim 23,wherein the superiorly extending portion includes a second axle passageconfigured to align with the first axle passage when the superiorlyextending portion is inserted between the medial and lateral walls. 29.The knee prosthesis system of claim 28, wherein the second axle passageis oblong.
 30. The knee prosthesis system of claim 28, furthercomprising an axle configured to extend through the first and secondaxle passages when the superiorly extending portion is inserted betweenthe medial and lateral walls.
 31. The knee prosthesis system of claim23, wherein the superior surface of the platform and the bearing portionare connected via a tray insert.
 32. The knee prosthesis system of claim31, wherein the tray insert permits the bearing portion to rotaterelative to the superior surface.
 33. The knee prosthesis system ofclaim 20, further comprising a fastener configured to couple the femoralcomponent insert to the femoral component.